If you have good credit you should be able to get in the 5.5-5.75% range for your refinance.  

You've got a wide range of responses already here and it most certainly depends on your market! 

You can get solid cash-flowing single families in the 90-120k price range and duplexes in the 130-180k price range.

Speak to your lender/broker for a closing costs estimate, which will be much more accurate than a percentage range. 

Balloons coming due with higher interest rates, China market, China production, Manufacturing production moving back to the US, Worker shortages, Workert pay hikes, Ukraine/Russia food and fertilizer misses, Oil prices increasing due to the OPEC Q1 production curtailments in place, Houthi issues, Panama Canal Water issues, Illegal immigration impact (buy one of those office buildings and rent for $10mm per year for Illegal housing, take advantage) social benefits required, Climate change believe it or not- Buy or sell into that thought process,  US politics, Baby boomers leaving workforce and needing more benefits, Baby Boomers moving from Stocks to Bonds,  etc.I agree things will get worse, but that means more investing opportunities. 

As for statistics on wrongful imprisonment, a quick search comes up with numerous sources in the 2%-5% range.

My houses are usually in the $200K-$250K range

I ran number multiple times but my estimation seems not great as I am not sure what percentage I should allocate monthly expenses as the recommandation is a range such as 5%~15%.

The building is in a cheaper suburb value only $250k range so I want to get this done affordably and need do all 4 units.

Moving a gas appliance (range, or furnace) would require a permit.